This invention relates to cache control in I/O processing using a cache area provided in a server and a storage system.
In recent years, nonvolatile memories (NVM) such as a flash memory are used in various electronic devices. Unlike a hard disk drive (HDD), the nonvolatile memory does not involve a mechanical operation, and permits faster access than the HDD.
Nonvolatile memories are also used in enterprise applications such as a server and a storage system that need fast data access. Particularly, nonvolatile memories mountable in servers become inexpensive, and are thus becoming popular.
There have been proposed various computer systems that achieve fast data access by using a volatile memory and a nonvolatile memory which are included in a server (see, for example, the description of US 2009/0024793 A1). US 2009/0024793 A1 describes cache control in a system having a memory for data cache different from a main memory. When writing of data onto a disk is detected, for example, a device driver determines whether or not the data can be written into the memory for data cache, pushes out data from the memory for data cache if necessary, and writes the requested data therein.